The present invention is directed generally to a hot water dispensing apparatus, and more particularly to a boiling water dispenser capable of dispensing large volumes of water at boiling temperature.
It is frequently desirable in restaurants and other commercial cooking establishments to have a source of hot water for various cooking purposes, such as the preparation of pastas, potatoes, gravies, soups and similar dishes, as well as for various cleaning purposes To supply hot water for these and other purposes hot water dispensers have come into increasing use. Typically, these units employ a hot water reservoir in which water is heated by an electric resistance heater element The application of electric current to the heating element is typically controlled by various means responsive to a temperature sensing element in the reservoir, such as a thermistor, to achieve a predetermined dispensing temperature. One successful commercial version of such a hot water dispenser is the Model HW-5 Hot Water Machine manufactured by Bunn-O-Matic Corporation of Springfield, Ill., U.S.A.
In many applications it is desirable that the hot water be dispensed at boiling temperature This requires that the temperature in the reservoir be maintained at the actual boiling point of the water in the reservoir. If the temperature is maintained too high, the water will continuously boil in the reservoir, resulting in a noisy, energy inefficient and steamy dispenser. If the temperature is maintained too low, the dispensed water will not be at boiling temperature and therefore unsuitable for its intended purpose. Since the actual boiling point of water in the reservoir will vary from batch to batch with changes in mineral content, elevation and barometric pressure, the use of a temperature sensing element in the reservoir does not provide satisfactory temperature control over an extended period of use.
The present invention provides a boiling water dispenser wherein temperature control is effected by sensing the initial occurrence of boiling of the water in the reservoir, and maintaining a level of excitation to the reservoir heating element which maintains this condition. This results in water always being dispensed from the reservoir at its actual boiling point
Accordingly, it is a general object of the present invention to provide a new and improved hot water dispenser.
It is a more specific object of the present invention to provide a boiling water dispenser which efficiently dispenses large volumes of water at its actual boiling temperature.